1. Field of the Invention
The present invention relates to a method of polishing or grinding metal plates or metal strips such as steel plates or sheets, thin steel plates, etc. in making steel into a strip. The invention more particularly concerns with a method of polishing or grinding metal strips running longitudinally thereof in a process, the method comprising brushing or polishing the metal strip with a brush roll rotated in contact with the strip surface under a pressure while supplying a mixture of a grinding fluid or water with abrasive grains to a portion of metal strip to be brushed or polished.
2. Description of the Prior Art
Such methods of polishing metal strips are known. For example, the methods have been heretofore employed for polishing or grinding steel strips with good results in making steel into a strip. However, if a metal strip has pinholes, pits or the like, the methods can not polish the defective spots except by grinding the strip to the level of indent bottom. The grinding to the level of indent bottom decreases the productivity and increases the consumption of brush roll and the loss of metal material. Hence it raises the production cost and is undesirable. Further, some metal strips provided in making steel into a strip have these defects as is well known in the art.